I watched the the launch of the New Horizons spacecraft in 2006, and it is still one of my favorite memories. It took 10+ years to get the photographs it took of Pluto back, and that was a bit like re-living it all over again. (And worth the wait, what a great set of photos it was!) I would definitely recommend going and seeing one, and pick something that is interesting to you if you can. If not, any old launch will be fun to watch anyway.